Google released Panda 4.2, the latest Panda algorithm update, in mid-July. If you didn’t feel an impact on your site’s performance on July 18, you’re not alone.

Panda 4.2 is Google’s latest algorithm update meant to fight web spam, specifically demoting sites in the rankings that contain duplicative or thin content. In other words, Panda targets sites that contain the same content as other sites and sites whose pages contain low-value content.

Despite Google’s estimation that Panda 4.2 would affect about two to three percent of English language queries, a medium-level algorithm update for Google, affected sites may not feel traceable impact for months. This is the slowest moving algorithm that we know of — past Panda updates fully rolled out within days or weeks. Google Webmaster Trends Analyst John Mueller attributes the slow rollout to unspecified technical reasons.

This is the slowest moving algorithm that we know of — past Panda updates fully rolled out within days or weeks.

This update is troubling for organic search marketers because it’s a reversal of Google’s recent statements on its rollout process. Despite its March 2015 statement that Panda algorithm updates respectively would shift to “continuous updates,” we now know that we’re still tied to irregular, periodic releases. And in this case, it’s slower than ever before.

Why Algorithm Update Speed Matters

It sounds pretty tedious and unrelated, I know, but how Google rolls out its algorithm updates has direct impact on ecommerce businesses.

Regardless of the reason that the rollout is slower this time, the result is that it will be difficult to trace the impact of Panda 4.2 to your site’s organic search performance. In the past, a quick Panda algorithm rollout resulted in a sudden drop in Google search performance if a site was impacted. Tracing that drop in performance to the specific date of the update at least allowed affected sites to understand the source of the issue.

Panda 4.2 would string that performance decrease over several months, and also perhaps with different pages seeing a decrease in performance at different times. The resulting trend in web analytics could be a long slow slide down as opposed to the sharp, sudden decrease we’ve been used to seeing in the past.

In addition, the Panda algorithm impacts an entire site, as opposed to limiting the impact to individual pages on a site. But the changes in performance could hit different pages at different times over the months-long rollout period, which again makes it all the more difficult to trace the issue back to Panda 4.2.

If you can’t trace an issue to a probable cause, it’s all the more difficult to resolve the issue.

The other reason that a slow rollout matters is that sites that have improved their content since being caught up in previous Panda algorithm updates will have to wait longer to see the full positive impact of their efforts.

The other reason that a slow rollout matters is that sites that have improved their content since being caught up in previous Panda algorithm updates will have to wait longer to see the full positive impact of their efforts.

For example, a site that was penalized in the Panda 4.1 update on September 25, 2014, would have in the past seen a sharp increase in its performance on that day or week if Panda 4.1 determined that the site had been improved. With Panda 4.2, the positive impact will be as slow as the downward slide will be for newly penalized sites. It will be more difficult to determine that all your hard work to escape Panda’s grasp have paid off.

How Panda Works

The Panda algorithms require updates, while other algorithms work in an “everflux” mode that continually alter search results. Think of Panda like a filter that collects sites that don’t pass quality standards. Panda’s filter collects site data for months and months, until at some point the update is rolled out and the data is refreshed.

The data refresh essentially applies the ranking demotion effects of the algorithm to all of those sites that the Panda filter had been collecting. This happens traditionally two or three times a year, but in this case the last update and its refresh occurred 10 months ago.

Ten months is a long time to wait to see if your site has passed Panda’s quality standards and recovered its rankings and traffic. For an ecommerce site, the length of time between updates can have a material impact on its business.

Another web spam algorithm, Penguin, which focuses on demoting sites with unnatural backlink profiles, has historically worked the same way that Panda does. Late last year, however, Google announced that Penguin would switch to an everflux state, but has recently confirmed that it won’t achieve this for months.

We know that Google is working on speeding up the length of time between updates, and eventually achieving the everflux state. This is good news for ecommerce sites that have been penalized by Panda or Penguin, but it also means that you could be penalized anew at any point as well. In addition, everflux means that there will be no more algorithm release updates, which in turn means that there will be no milestone dates with which to pinpoint the cause of performance changes.